1100 Superior

1100 Superior (formerly known as the Diamond Shamrock Building, the Diamond Building, and Oswald Centre) is a skyscraper in downtown Cleveland, Ohio's emerging Nine-Twelve District, which is also home to One Cleveland Center, Ohio Savings Plaza, The 925 Building, PNC Center, and the former Eaton Center. It was built in 1972 for the important San Antonio, Texas firm of Diamond Shamrock which specialized in oil refining, it has 23 floors and rises to a height of 282 feet (86 m).[1] It was designed by the firm of Skidmore, Owings and Merrill which also designed the nearby AECOM Building, and the Willis Tower in Chicago, Illinois. The firm was a leader in the modernist tower block design at the time of construction which believed in three principals: heavy metal anchoring, profuse windows for air and light, and simple muted dark colored facade paneling that gave their landmark buildings a "natural" organic look.

1100 Superior
The Diamond Shamrock Building (now 1100 Superior) rises behind Chester Commons (now Perk Park) in 1973
1100 Superior
Former names	Diamond Shamrock Building Diamond Building
Alternative names	Oswald Centre
General information
Status	Complete
Type	High-rise
Architectural style	International
Classification	Office
Location	Nine-Twelve District
Address	1100 Superior Avenue
Town or city	Cleveland, Ohio
Coordinates	41°30′10.15″N 81°41′11.17″W
Construction started	1971 (1971)
Completed	1972 (1972)
Owner	American Landmark Properties, Ltd.
Landlord	Kowit & Passov Real Estate Group
Height
Architectural	282 feet (86 m)
Tip	282 feet (86 m)
Roof	282 feet (86 m)
Technical details
Floor count	23
Floor area	27,677 square feet (2,571.3 m2)
Grounds	550,000 square feet (51,000 m2)
Design and construction
Architecture firm	Skidmore, Owings & Merrill, LLP
Structural engineer	Skidmore, Owings & Merrill, LLP
Main contractor	Turner Construction
Other information
Number of restaurants	2
Parking	Attached garage - 335 spaces
Website
1100superior.com

It is located at 1100 Superior Avenue along East 12th Street. In 1994, during a water main break, a four-story section of the Diamond Building lost some of its glass from pressure of the water. In 2012, the tower's naming rights were purchased by insurance brokerage the Oswald Cos. (which is written in bright red multistory letters on the north and south sides of the tower), one of its largest tenants.[2]